Properties of Halococcus salifodinae, an Isolate from Permian Rock Salt Deposits, Compared with Halococci from Surface Waters.

Halococcus salifodinae BIpT DSM 8989T, an extremely halophilic archaeal isolate from an Austrian salt deposit (Bad Ischl), whose origin was dated to the Permian period, was described in 1994. Subsequently, several strains of the species have been isolated, some from similar but geographically separated salt deposits. Hcc. salifodinae may be regarded as one of the most ancient culturable species which existed already about 250 million years ago. Since its habitat probably did not change during this long period, its properties were presumably not subjected to the needs of mutational adaptation. Hcc. salifodinae and other isolates from ancient deposits would be suitable candidates for testing hypotheses on prokaryotic evolution, such as the molecular clock concept, or the net-like history of genome evolution. A comparison of available taxonomic characteristics from strains of Hcc. salifodinae and other Halococcus species, most of them originating from surface waters, is presented. The cell wall polymer of Hcc. salifodinae was examined and found to be a heteropolysaccharide, similar to that of Hcc. morrhuae. Polyhydroxyalkanoate granules were present in Hcc. salifodinae, suggesting a possible lateral gene transfer before Permian times.

Influence of the collection and oxygenation method on quantitative bacterial composition in bronchoalveolar lavage fluid samples from healthy dogs.

The purpose of the study was to evaluate the effects on quantitative and qualitative microbial content of endoscopic bronchoalveolar lavage fluid (BALF) in healthy dogs using a laryngeal mask airway (LMA). It was hypothesised that oropharyngeal protection might prevent contamination of BALF with oropharyngeal microflora. Ten healthy Beagle dogs were randomly assigned to two groups and underwent endoscopic BAL on two occasions, either via an open unprotected oropharynx with oxygen supply provided via a nasal catheter (NT) or through a sterile LMA. For the second sampling, groups were switched. BALF analysis included quantitative microbial culture, nucleated cell counts and cytology. The mean (+/-SD) number of colony forming units (CFU)/mL found in the BALF using the LMA was 25,610+/-22,943 in the right lung (RL) and 22,510+/-18,779 in the left (LL). With the NT technique, the figures were 21,068+/-19,375 for the RL and 16,060+/-15,523 for the LL, respectively. Nucleated cell counts/microL were 691.0+/-181.6 (RL) and 734.0+/-171.6 (LL) for LMA, and 772.0+/-251.0 (RL) and 748+/-163.2 (LL) for NT. No significant differences were detected either in the number of CFU/mL or in the diversity of bacterial species with the two methods. A significant increase in BALF bacterial counts (with reduced species diversity) was observed on the second compared to the first sampling regardless of the method used. Protection of the oral cavity and oropharynx using an LMA had no significant influence on BALF bacterial counts. The findings suggest that with careful endoscope insertion, the risk of contamination of BALF by resident and transient oropharyngeal microflora can be negligible.

DGGE and real-time PCR analysis of lactic acid bacteria in bacterial communities of the phyllosphere of lettuce.

Food associated indigenous microbial communities exert antagonistic effects on pathogens and may routinely deliver health relevant microorganisms to the GI tract. By using molecular, culture independent methods including PCR-DGGE of 16S rDNA-coding regions and real-time PCR (RT-PCR) as well as BIOLOG metabolic fingerprinting, microbial communities on lettuce were analyzed in samples from fields, from supermarkets and soil. Amplified 16S rRNA gene sequences (57.7%) could be assigned to species previously reported as typical for the phyllosphere including Pantoea agglomerans, Pseudomonas flavescens, Moraxella spp., and Mycobacterium spp. 71.8% of the sequences obtained represented so far undescribed taxa. Principal component analysis of BIOLOG metabolic profiles indicated a seasonal variation in the lettuce phyllosphere microbial community structure. Various lactic acid bacteria were detected including several Lactobacillus and Leuconostoc species in particular on lettuce from organic farming. By RT-PCR lactobacilli were found with a range of abundances from 1x10(4 )to 1x10(5 )copies/g lettuce. Considering the importance of salad in many diets lettuce may contribute to a constant supply with LAB.

Proposal of Hymenobacter norwichensis sp. nov., classification of 'Taxeobacter ocellatus', 'Taxeobacter gelupurpurascens' and 'Taxeobacter chitinovorans' as Hymenobacter ocellatus sp. nov., Hymenobacter gelipurpurascens sp. nov. and Hymenobacter chitinivorans sp. nov., respectively, and emended description of the genus Hymenobacter Hirsch et al. 1999.

Two airborne bacterial isolates, NS/2 and NS/50(T), were examined in order to determine their taxonomic position. Their almost complete 16S rRNA gene sequences shared 95.9 % similarity. Sequence comparisons demonstrated that their next relatives are species of the genus Hymenobacter (93.6-95.7 % similarity) and the strains 'Taxeobacter chitinovorans' Txc1(T), 'Taxeobacter gelupurpurascens' Txg1(T) and 'Taxeobacter ocellatus' Myx 2105(T) (90.5-96.4 %). Phylogenetic calculations indicated that these five strains together with the three recognized Hymenobacter species form a separate line of descent within the family 'Flexibacteraceae'. Isolates NS/2 and NS/50(T), as well as 'Taxeobacter chitinovorans' Txc1(T), 'Taxeobacter gelupurpurascens' Txg1(T) and 'Taxeobacter ocellatus' Myx 2105(T), possessed the characteristics of the genus Hymenobacter, the quinone system menaquinone MK-7 and a polyamine pattern with the major polyamine being sym-homospermidine. Each of the five strains had complex, unique polar lipid profiles, with phosphatidylethanolamine and several unknown aminophospho-, amino-, phospho-, glyco- and polar lipids of which several compounds were also found in established Hymenobacter species. All the strains studied possessed fatty acids characteristic of Hymenobacter species, including major acids iso-C(15 : 0), anteiso-C(15 : 0), C(16 : 1)omega5c, summed feature 3 (C(16 : 1)omega7c/iso-C(15 : 0) 2-OH) and summed feature 4 (iso-C(17 : 1) I/anteiso-C(17 : 1) B). The five strains could be distinguished from each other and from the three established species of the genus Hymenobacter based on relatively low 16S rRNA gene sequence similarities (<97 %), unique polar lipids and differing fatty acid profiles and physiological characteristics. In conclusion, the description of four novel species of the genus Hymenobacter appears to be justified, for which the names Hymenobacter norwichensis sp. nov. (type strain NS/50(T)=LMG 21876(T)=DSM 15439(T)), Hymenobacter chitinivorans sp. nov. (type strain Txc1(T)=LMG 21951(T)=DSM 11115(T)), Hymenobacter gelipurpurascens sp. nov. (type strain Txg1(T)=LMG 21874(T)=DSM [corrected][11116(T)) and Hymenobacter ocellatus sp. nov. (type strain Myx 2105(T)=Txo1(T)=LMG 21873(T)=DSM 11117(T)) are proposed. For strain NS/2, a description only is provided without proposal of a name because its status as a novel species was not demonstrated unambiguously.

Rubellimicrobium thermophilum gen. nov., sp. nov., a red-pigmented, moderately thermophilic bacterium isolated from coloured slime deposits in paper machines.

Six red-pigmented strains of the Alphaproteobacteria with optimal growth between 45 and 54 degrees C were previously isolated from coloured biofilms in two fine-paper machines and one pulp dryer. The strains were found to be resistant to 15 p.p.m. 2,2-dibromo-3-nitrilopropionamide, a common industrial biocide. 16S RNA gene sequence similarity of the isolates was 99.7-100 %. Ribotyping using the restriction enzymes PvuII and EcoRI showed that four of the isolates (C-lvk-R2A-1, C-lvk-R2A-2(T), C-R2A-52d and C-R2A-5d) belong to a single species. 16S rRNA gene-based phylogenetic analysis revealed that, together with Rhodobacter blasticus ATCC 33485(T), the isolates form a deep line of descent (94.7-94.9 % sequence similarity) within the family Rhodobacteraceae loosely affiliated with the Rhodobacter/Paracoccus clade. The isolates were strictly aerobic and oxidase-positive (catalase was weakly positive) and utilized a wide range of substrates including pentoses, hexoses, oligosaccharides and sugar alcohols. The predominant constituents in their cellular fatty acid profiles were C(19 : 0) cyclo omega8c (39-44 %), C(18 : 0) (21-24 %) and C(16 : 0) (21-23 %). Fatty acids present in smaller amounts included C(18 : 1)omega7c, C(10 : 0) 3-OH, C(18 : 1)omega7c 11-methyl, C(20 : 2)omega6,9c and C(17 : 0) cyclo, amongst others. Polar lipids included diphosphatidylglycerol, phosphatidylcholine and an unidentified aminolipid, but not phosphatidylethanolamine. Carotenoid pigments were synthesized but bacteriochlorophyll a was not. The polyamine patterns consisted of the major compounds putrescine, spermidine and sym-homospermidine. The major respiratory lipoquinone was ubiquinone Q-10. The DNA G+C content was 69.4-70.2 mol%. On the basis of the phylogenetic and phenotypic evidence, the biofilm isolates were classified in a new genus, Rubellimicrobium gen. nov.; four of the isolates are assigned to the type species, Rubellimicrobium thermophilum gen. nov., sp. nov. Strain C-lvk-R2A-2(T) (=CCUG 51817(T) = DSM 16684(T) = HAMBI 2421(T)) is the type strain of Rubellimicrobium thermophilum.

Sphingomonas aurantiaca sp. nov., Sphingomonas aerolata sp. nov. and Sphingomonas faeni sp. nov., air- and dustborne and Antarctic, orange-pigmented, psychrotolerant bacteria, and emended description of the genus Sphingomonas.

Seven psychrotolerant, Gram-negative bacterial strains, five dust- and airborne isolates (MA101b(T), MA306a, MA405/90, MA-olki(T) and NW12(T)) and two from the Antarctic (Ant 20 and M3C203B-B), were subjected to a polyphasic characterization to determine their taxonomic position. High 16S rDNA sequences similarities (99.3-100.0 %) demonstrated that they were closely related to each other. Phylogenetic evaluation of their 16S rDNA sequences revealed that they are members of the genus Sphingomonas sensu stricto, encompassing a separate branch within this genus. They shared 94.4-96.6 % 16S rDNA sequence similarity with species of this genus. All Sphingomonas-specific signature nucleotides were also detected. The presence of the major ubiquinone Q-10, sym-homospermidine as the predominant polyamine, Sphingomonadaceae-specific sphingoglycolipid in the polar lipid patterns and a fatty acid profile containing C(14 : 0) 2-OH and lacking 3-OH fatty acids were in agreement with identification of these strains as members of the genus Sphingomonas sensu stricto. Results from DNA-DNA hybridizations and comparison of protein patterns indicated that the seven strains are members of three distinct species. One species is represented by strains MA101b(T), MA306a and MA405/90, the second by strains NW12(T), Ant 20 and M3C203B-B and the third by one strain, MA-olki(T). Their distinction at the species level was also supported by results of biochemical characterization and partly supported by riboprints and genomic fingerprints. On the basis of these results, three novel species of the genus Sphingomonas are proposed: Sphingomonas aurantiaca sp. nov., consisting of strains MA101b(T) (=DSM 14748(T)=LMG 21377(T)), MA306a and MA405/90 (=DSM 14749=LMG 21378), Sphingomonas faeni sp. nov. MA-olki(T) (=DSM 14747(T)=LMG 21379(T)) and Sphingomonas aerolata sp. nov., represented by strains NW12(T) (=DSM 14746(T)=LMG 21376(T)), Ant 20 (=ICMP 13599) and M3C203B-B (=SMCC M3C203B-B).

Sterolibacterium denitrificans gen. nov., sp. nov., a novel cholesterol-oxidizing, denitrifying member of the beta-Proteobacteria.

A bacterial strain (Chol-1S(T)) that is able to oxidize cholesterol to CO2 and reduce nitrate to dinitrogen was enriched and isolated from an upflow sludge bed (USB) anoxic reactor that treats sanitary landfill leachate from the city of Montevideo, Uruguay. Cells of strain Chol-1S(T) were gram-negative, rod-shaped to slightly curved, measured 0.5-0.6 x 1.0-1.3 microm and were motile by a single polar flagellum. Strain Chol-1S(T) grew optimally at 30-32 degrees C and pH 7.0, with a doubling time of 44-46 h when cholesterol was used as the sole carbon and energy source. The metabolism of strain Chol-1S(T) was strictly respiratory, with oxygen or nitrate as the terminal electron acceptor. The presence of ubiquinone Q-8 as the sole respiratory lipoquinone indicated that strain Chol-1S(T) belonged to the beta-subclass of the Proteobacteria. Phosphatidylethanolamine was the predominant polar lipid and the G + C content of the DNA was 65.3 mol%. The fatty acid profile of strain Chol-1S(T), cultivated under denitrifying conditions by using a defined mineral medium supplemented with cholesterol, was characterized by the following major components: summed feature 4 (C16:1 omega7c and/or iso C15:0 2-OH), C16:0, C18:1 omega7c and hydroxy acid C10:0 3-OH. Minor components included C10:0, C11:0, C12:0, C14:0, C15:0, C19:0, C19:0 10-methyl and hydroxylated acids C8:0 3-OH and C16:0 3-OH. Analysis of the 16S rDNA sequence showed that strain Chol-1S(T) represents a separate lineage within the Thauera, Azoarcus, Zoogloea and Rhodocyclus assemblage of the beta-Proteobacteria. Strain Chol-1S(T) had highest sequence similarity (96.5%) with strain 72Chol, a denitrifying beta-Proteobacterium. On the basis of polyphasic evidence, strain Chol-1S(T) (=DSM 13999T=ATCC BAA-354T) is proposed as the type strain of Sterolibacterium denitrificans gen. nov., sp. nov.

Aurantimonas coralicida gen. nov., sp. nov., the causative agent of white plague type II on Caribbean scleractinian corals.

A bacterium previously isolated from a diseased colony of the scleractinian coral Dichocoenia stokesi (common name elliptical star coral) was subjected to a detailed polyphasic taxonomic characterization. The isolate, designated WP1T, was halophilic and strictly aerobic and formed golden-orange-pigmented colonies after prolonged incubation. Cells of WP1T were gram-negative, rod-shaped and showed a characteristic branching rod morphology. Chemotaxonomically, WP1T was characterized by having Q-10 as the major respiratory lipoquinone and sym-homospermidine as the main component of the cellular polyamine content. The predominant constituent in the cellular fatty acid profile was C18:1 omega7c, along with C19:0 cyclo omega8c and C16:0. Other fatty acids present in smaller amounts were C17:0, C18:0, C16:1 omega7c, C20:1 omega7c and C18:1 2-OH. The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol and phosphatidylcholine. Minor amounts of diphosphatidylglycerol, phosphatidylmonomethylethanolamine and phosphatidyldimethylethanolamine were present. The G + C content of the genomic DNA was 66.3 mol%. Phylogenetic analysis of the 16S rRNA gene sequence showed that WP1T represents a separate subline of descent within the order 'Rhizobiales' of the 'Alphaproteobacteria'. The new line of descent falls within the group of families that includes the Rhizobiaceae, Bartonellaceae, Brucellaceae and 'Phyllobacteriaceae', with no particular relative within this group. The 16S rRNA gene sequence similarity to all established taxa within this group was not higher than 92.0% (to Mesorhizobium mediterraneum). To accommodate this emerging coral pathogen, the creation of a new genus and species is proposed, Aurantimonas coralicida gen. nov., sp. nov. (type strain WP1T = CIP 107386T = DSM 14790T).

Erythrobacter citreus sp. nov., a yellow-pigmented bacterium that lacks bacteriochlorophyll a, isolated from the western Mediterranean Sea.

Two facultatively oligotrophic, intensely yellow-pigmented bacterial strains, RE35F/1T and RE10F/45, have been previously isolated from the western Mediterranean Sea (Bay of Calvi, Corsica, France) by 0.2 microm membrane filtration. The organisms were gram-negative, catalase- and oxidase-positive, strictly aerobic, rod-shaped and non-motile. Their respiratory lipoquinone profiles consisted exclusively of ubiquinone-10 (Q-10) and the G+C contents of their DNAs were 62.0 and 62.4 mol%, respectively. Among the cellular fatty acids, octadecenoic acid (18:1omega7c) was the major component. Both isolates also contained hydroxy fatty acids (14:0 2-OH, 18:1 2-OH and 16:0 iso 3-OH) and branched fatty acids (15:0 anteiso, 16:0 anteiso and 17:0 anteiso). Polar lipid fingerprints were characterized by the presence of a sphingoglycolipid. Comparative analyses of their 16S rRNA gene sequences indicated that both isolates were phylogenetically closely related (sequence similarity of 99.9%) and formed a coherent cluster with aerobic bacteriochlorophyll a-containing species of the Erythrobacter/Porphyrobacter/Erythromicrobium cluster within the family Sphingomonadaceae. The closest relative was Erythrobacter litoralis DSM 8509T (97.4 and 97.5% 16S rRNA gene sequence similarity between this strain and RE35F/1T and RE10F/45, respectively). DNA-DNA reassociation studies confirmed that strains RE35F/1T and RE10F/45 represent a single species (79.6% DNA homology), but also demonstrated that they do not belong to the species Erythrobacter litoralis (25.2 and 34.2% DNA homology, respectively). Notably, both RE35F/1T and RE10F/45 lacked bacteriochlorophyll a. Based upon phenotypic and molecular evidence, a novel species of the genus Erythrobacter, Erythrobacter citreus sp. nov., is proposed. Strain RE35F/1T (= CIP 107092T = DSM 14432T) is the type strain.

Novosphingobium hassiacum sp. nov., a new species isolated from an aerated sewage pond.

The taxonomy of two strains W-51T and W-52 isolated from a wastewater treatment plant was investigated in a polyphasic approach. The yellow pigmented gram-negative organism contained a quinone system with mainly ubiquinone Q-10, and the polar lipid profile contained a sphingoglycolipid suggesting that both strains belonged to the the alpha-4 subclass of the Proteobacteria. The polar lipid profile consisted furthermore of phosphatidylethanolamine, diphosphatidylglycerol, and phosphatidylcholine and of minor amounts of phosphatidylglycerol and phosphatidylmonomethylethanolamine. Sequencing of the 16S rRNA gene supported the allocation into the genus Novosphingobium, together with the type strains of N. subterraneum, N. aromaticivorans, N. stygium, and N. capsulatum, showing similarities of 97.3%, 97.0%, 95.7% and 96.2%, respectively. This allocation was supported by the polyamine profile, which consisted mainly of spermidine. The analysis of the fatty acids revealed 2-OH 13:0, 2-OH 14:0 and 2-OH 15:0, with 2-OH 15:0 as predominant hydroxylated fatty acid. W-51T and W-52 were almost identical with respect to their phenotypic including the majority of the chemotaxonomic properties, identical in their 16S rRNA sequences, and showed 86% DNA-DNA similarity. Both strains were able to reduce nitrate and on the basis of further physiological features, a clear differentiation from all other Novosphingobium species was possible. The DNA-DNA similarities of W-51T to the type strains of N. subterraneum, N. aromaticivorans, and N. capsulatum were below 56%. For these reasons, it is proposed to create a new species with the name Novosphingobium hassiacum sp. nov.

Classification of three airborne bacteria and proposal of Hymenobacter aerophilus sp. nov.

Three aerobic, gram-negative, rod-shaped, non-spore-forming, red-pigmented, airborne bacteria (I/26-Cor1T, I/32A-Cor1 and I/74-Cor2) collected in the Museo Correr (Venice, Italy) were investigated to determine their taxonomic status by analysing their biochemical, physiological and chemotaxonomic features and the G+C content of genomic DNA and by comparing their genomic fingerprints. Additionally, the almost complete 16S rRNA gene sequence of strain I/26-Cor1T was analysed. The three strains were nearly identical in their morphological, physiological, biochemical and chemotaxonomic properties. The strains contained a menaquinone system with the predominant menaquinone MK-7 and a fatty acid profile with C15:0 anteiso, C15:0 iso and C16:1 predominant. Phosphatidylethanolamine and several unidentified lipids were detected in the polar lipid profiles. The polyamine pattern consisted of sym-homospermidine as the major compound. meso-Diaminopimelic acid was found as the characteristic cell-wall diamino acid. The DNA base composition of the three strains ranged from 60 to 63 mol% G+C. Phylogenetically, strain I/26-Cor1T was most closely related to Hymenobacter actinosclerus (95.8% 16S rRNA gene sequence similarity). Physiological and genomic characteristics indicated that the two strains I/26-Cor1T and I/32A-Cor1 are representatives of the same species. The phylogenetic distance to any validly described taxon as indicated by 16S rRNA gene sequence similarities demonstrates that I/26-Cor1T and I/32A-Cor1 represent a novel species, for which the name Hymenobacter aerophilus sp. nov. is proposed, with the type strain I/26-Cor1T (= DSM 13606T = LMG 19657T). I/32A-Cor1 (= DSM 13607 = LMG 19658) is another strain of the species Hymenobacter aerophilus. Since the taxonomic status of strain I/74-Cor2 within the genus Hymenobacter was not determined unambiguously, it is designated Hymenobacter sp. I/74-Cor2 (= DSM 13611 = LMG 19659).

Vibrio calviensis sp. nov., a halophilic, facultatively oligotrophic 0.2 microm-fiIterabIe marine bacterium.

A gram-negative, facultatively anaerobic, straight to slightly curved rod-shaped bacterium (RE35F/12T) sensitive to vibriostatic agent O/129 was previously isolated from sea water (Western Mediterranean Sea, Bay of Calvi, Corsica, France) by 0.2 microm-membrane filtration. Strain RE35/F12T (= CIP 107077T = DSM 14347T) was facultatively oligotrophic, halophilic, required Na+ for growth and produced acid but no gas from D-glucose under anaerobic conditions. Comparative 165 rRNA gene-sequence analyses demonstrated that the bacterium is most closely related (94.3%) to Vibrio scophthalmi. Similarities to the sequences of all other established Vibrio species ranged from 93.6% (with Vibrio aestuarianus) to 90.7% (with Vibrio rumoiensis). Strain RE35/F12T occupies a distinct phylogenetic position; this is similar to the case of Vibrio hollisae, because RE35F/12T represents a relatively long subline of descent sharing a branching point with the outskirts species V. hollisae. The G+C content of the DNA was 49.5 mol%. Ubiquinone Q-8 was the main respiratory lipoquinone, and 16:1omega9cis, 16:0 and 18:1trans9, cis11 were the major cellular fatty acids, 16:1omega9cis being predominant. The polyamine pattern was characterized by the presence of the triamine sym-norspermidine. On the basis of the polyphasic information summarized above, a new Vibrio species is described for which the name Vibrio calviensis sp. nov. is proposed.

Emended descriptions of the genus Micrococcus, Micrococcus luteus (Cohn 1872) and Micrococcus lylae (Kloos et al. 1974).

Nine yellow-pigmented, spherical bacterial strains isolated from a medieval wall painting (strain D7), from indoor air (strains 3, 6, 7, 13C2, 38, 83 and 118) and from an activated-sludge plant (strain Ballarat) were classified by a polyphasic approach. Analyses of the 16S rRNA gene sequences of three representatives (strains D7, 118 and Ballarat) indicated that they all belong to the genus Micrococcus. The three isolates shared the highest sequence similarities with Micrococcus luteus DSM 20030T (97.9-98%), Micrococcus antarcticus AS 1.2372T (97.9-98.3%) and Micrococcus lylae DSM 20315T (97.5-97.9%). DNA-DNA reassociation studies clearly demonstrated that all nine isolates belong to the species M. luteus. However, neither their chemotaxonomic features nor their physiological and biochemical properties were consistent with those of M. luteus DSM 20030T. In contrast to M. luteus DSM 20030T, all isolates investigated possessed MK-8(H2) as the major respiratory quinone, and strain Ballarat had an A4alpha peptidoglycan type. On the basis of analyses of their Fourier transform-infrared spectroscopy spectra, isolates D7, 3, 6, 7, 13C2, 38, 83 and 118 could be grouped into a single cluster separate from M. luteus DSM 20030T, strain Ballarat and M. lylae DSM 20315T. In addition, all these isolates could be distinguished from M. luteus DSM 20030T by their ability to assimilate D-maltose, D-trehalose, DL-3-hydroxybutyrate, DL-lactate, pyruvate and L-histidine and to hydrolyse casein. Strains D7, 3, 6, 7, 13C2, 38, 83 and 118 differed from both M. luteus DSM 20030T and strain Ballarat by their ability to assimilate acetate, L-phenylalanine, L-serine and phenylacetate. Furthermore, REP-PCR fingerprinting yielded one common band for these strains, whereas this band was not observed for M. luteus DSM 20030T, strain Ballarat or M. lylae DSM 20315T. On the basis of these data, the species M. luteus can be divided into three biovars that are distinguished by several chemotaxonomic and biochemical traits: biovar I, represented by M. luteus DSM 20030T; biovar II, represented by strains D7 (= DSM 14234 = CCM 4959), 3, 6, 7, 13C2, 38, 83 and 118; and biovar III, represented by strain Ballarat (= DSM 14235 = CCM 4960). On the basis of the results generated in this study, emended descriptions of the genus Micrococcus and the species M. luteus and M. lylae are given.

Sphingopyxis witflariensis sp. nov., isolated from activated sludge.

Classification of strain W-50(T), which was isolated from a wastewater treatment plant, was investigated by a polyphasic approach. Cells of strain W-50(T) were Gram-negative, strictly aerobic, oxidase-positive and yellow-pigmented. Ubiquinone Q-10 was the main respiratory lipoquinone system and polar lipid fingerprints were characterized by the presence of a sphingoglycolipid, suggesting that strain W-50(T) belongs to the alpha-4 subclass of the Proteobacteria. Sequencing and comparative analyses of the 16S rRNA gene of strain W-50(T) supported its chemotaxonomic allocation as an alpha-4 proteobacterium. The most closely related established taxa were species of the genus Sphingopyxis, including Sphingopyxis macrogoltabida (97.3% similarity) and Sphingopyxis terrae (96-4% similarity), and Sphingomonas taejonensis (97.3%). These findings were supported by both the polyamine content, which consisted mainly of spermidine [12.9 micromol (g dry wt)(-1)], and the presence of 2-OH 14:0, 2-OH 15:0 and 2-OH 16:0 in the cellular fatty acid profile. DNA-DNA hybridization experiments resulted in similarity values of 31.9% between strain W-50(T) and Sphingopyxis macrogoltabida IFO 15033(T), 44.9% between strain W-50(T) and Sphingopyxis terrae IFO 15098(T) and 31.0% between strain W-50(T) and Sphingomonas taejonensis KCTC 2884(T). Based upon results obtained by detailed physiological/biochemical testing and previously published molecular evidence, strain W-50(T) was clearly distinguishable from all other Sphingopyxis species. For these reasons, the creation of a novel species, Sphingopyxis witflariensis sp. nov., is proposed; strain W-50(T) (= DSM 14551(T) = CIP 107174(T)) is the type strain.

Very similar strains of Halococcus salifodinae are found in geographically separated permo-triassic salt deposits.

The authors have previously isolated a novel extremely halophilic archaeon, Halococcus salifodinae Blp, from Austrian rock salt deposited about 250 million years ago. In this study they compared strain Blp with two other halococci isolated independently from geographically distant salt deposits of similar age, and with two recent isolates (N1 and H2) from the same site as strain Blp. Strain BG2/2 was from a salt mine in Germany and strain Br3 from a halite deposit in England; both resembled Hc. salifodinae Blp in cellular and colonial morphology. Strains Blp, BG2/2 and Br3 had identical 16S rRNA sequences, very similar whole-cell protein patterns, which were different from those of other halococci, similar G+C contents and identical sequences in a 108-base insertion in their 5S rRNA gene. Other similarities included composition and relative abundances of polar lipids, antibiotic susceptibility, enzymic activities and Fourier-transform infrared spectra. Strains N1 and H2 showed similar morphology, whole-cell protein patterns and biochemical characteristics as strains Blp, Br3 and BG2/2. Their partial 16S rRNA sequences (682 and 641 bases, respectively) were indistinguishable from those of strains Blp, Br3 and BG2/2. Therefore strains N1 and H2 can be considered as reisolates of Hc. salifodinae which were obtained 8 years after the first samples were taken from that mine. The results presented suggest that viable halophilic archaea, which belong to the same species, occur in widely separated evaporite locations of similar geological age, and support the notion that these halophilic isolates from subterranean salt deposits may be the remnants of populations which inhabited ancient hypersaline seas.